Balanced slide-valve



(No Model.)

v G. SHONB.

BALANGED SLIDE VALVE.

No. 277,795. Patented May 15,1883.

\'Y Jf/ D UNlTED STATES` PATENT OFFICE.

. GEORGE SHONE, OF EAST ST. LOUIS, ILLINOIS.

vBALANCED SLIDE-VALVE;

SPECIFICATION forming part of Letters Patent No. 277,795, dated May 15,1883.

,-5- Application filed Junuaryd, 1883. (No model.)

To all whom it may concern:

Be it known that I, GEORGE SHONE, of East St. Louis, St. Clair county,State of Illinois, have invented a certain new and useful Improvement inBalanced Slide Valves, ot' which the following is a full, clear, andexact description, reference being had tothe accompanying drawings,forming part of this specication.

My improvement consists of a slide-valve having duplicate membersworking on opposite sides ofa valve-seat boxor casting, through whichthe steam -passages extend upward above the usual valve-seat. Thesemembers have end extensions that bear one against the other to relievethe working-faces from pressure ofthe steam upon their outer sides.Valves in the top of the seat-box allow the escape of steam from theexhausting end of the cylinder, it' at any time the pressure thereinexceeds the pressure in the steam-chest.

Figure l is a longitudinal section at l l, Fig. 5, the valves in centralposition. Fig. 2 is a horizontal section at 2 3, Fig. 4, the valvesbeing in position for the cylinder to take steam at one end and exhaustat the other; and Fig. 3 is a similar view, except that the valve is inthe reverse position. Fig. I is a side view. Fig. 5 is a top view. Fig.6 is a transverse section at 6 6, Fig. 2. Fig. 7 is a transverse sectionat 7 7, Fig. 2.

A is part of a steam engine cylinder, having steam -ports A' andexhaustport A2, as usual. Y

Bisthesteam-chest,madehigh enough to contain the valve-seat box orcast-ing C. The part C may be made separate from the cylinder A and ttedto the ordinary valve seat, A2, as

shown, and made fast thereto by screws; or`

it may be east in one piece with the cylinder.

- The steam-ports A' and exhaust-ports A2 ex- "Lis tend, as shown at A'XA' and A2", upward in the seat-box C, and each side of the box isdressed oft' into a valve-seat, O', substantially similar to that A3,the ports beingv closed at top, (and open to the sides.)

D is a slide-valve working upon the upright valve-seat G'. The valveproper is of the ordinary D form, but has extensions D' at each end.`These extensions or arms carry inwardly-extending bearing-plates D2. Thevalves are made in duplicate, as before stated,

| so that the steam -pressure is equal on each, and as the plates D2 atboth ends bear upon or against each other the valves are perfectlybalanced, and may be made to bear upon the seats C' as lightly as may beconsistent with tightness of lit, (to prevent the passage of steambetween the surfacesin contact.) Any wear,

-ing upward from the steam-ports A' to the steam-chest chamber, andsupplied with upwardly-openin g valves E' ,formin grelief-valves for thesteam in the exhausting end of the cylinder, it it at any time exceedsin pressure that of the live steam in the steam-chest.

F is a yoke surrounding the valves. Gis the valve-stem, giving means forthe working' of the valves in the usualmanner.

H is a horn entering the socketbearin g I, and senving to support thatend of the yoke.

The valves may be carried by the yoke, or may have bearing solely uponthe flange O2ot the valve-seat box C, or upon raised hearings upon saiditl-ange. Vhere the valves are supported on the yoke they are made withlips l)4 bearing thereupon.

It-will be seen that the ports A' and A2 in the valve-seatl box I) donot extend down to the lower edges ofthe valves D. Thus leakage ot'steam beneath the valves is prevented.

The operation of" my improvement is as follows: When the valves are ineither ofthe positions shown in Figs. 2 or 3 the live steam scendsthrough the port A' into the cylinder. (See Figs. 2 and 6.) Theexhaust-steam escapes 'rom the other end of the cylinder through theport A', chamber D5 of the valve, and through the exhaust-passage A2.

I claim- 1. In combination with a cylinder .having steam-ports A', acentral exhaust-port, A2, and a suitable steam-chest, of avalve-seat boxhaving extensions A'X A'X and A2X to the steam and exhaust ports, openat sides, and ports E, communicating with the extensions A'x A',

In the seat-box O are valve-ports E, extend-` enters the valve-seat boxhorizontally and deprovided with valves E E to relieve the ex- D2,openings D`,and chambers D5, and ayoke,

haust-stealn when atgreaterpressure than that F, substantially assetforth. within the steam-chest, as set forth. 2. Thecombinationofseat-boxhaving lsteam GEO' SHONE 5 and exhaust port extensions and valveseats Witnesses: l

.at the sides, a, slide-valve having extensions D l SAML. KNIGHT, ateach side,inwardly-extendingbearing-plates GEO. H. KNIGHT

